An investigation is performed into the efficiency of the
Streptomyces griseus
HUT 6037 enzyme immobilized in three different mesoporous silicas, namely mesoporous silica film, mesocellular foam, and ...rod-like SBA-15. It is shown that for all three supports, the pH value changes the surface charge and charge density and hence determines the maximum loading capacity of the enzyme. The products of the enzyme hydrolytic reaction are analyzed by
1
H-NMR. The results show that among the three silica supports, the mesoporous silica film (with a channel length in the range of 60-100 nm) maximizes the accessibility of the immobilized enzyme. The loading capacity of the enzyme is up to 95% at pH 7 and the activity of the immobilized enzyme is maintained for more than 15 days when using a silica film support. The order of the activity of the enzyme immobilized in different mesoporous silica supports is: mesoporous silica film > mesocellular foam > rod-like SBA-15. Furthermore, the immobilized enzyme can be easily separated from the reaction solution
via
simple filtration or centrifugation methods and re-used for hydrolytic reaction as required.
Mesoporous silica films were used as supports with high loading capacity and enzyme activity.
Colorectal cancer (CRC) is notable for its high mortality and high metastatic characteristics. The shear force generated by bloodstream provides mechanical signals regulating multiple responses of ...cells, including metastatic cancer cells, dispersing in blood vessels. We, therefore, studied the effect of shear flow on circulating CRC cells in the present study. The CRC cell line SW620 was subjected to shear flow of 12.5 dynes/cm2 for 1 and 2 h separately. Resulting elevated caspase‐9 and ‐3 indicated that shear flow initiated the apoptosis of SW620. Enlarged cell size associated with a higher level of cyclin D1 was coincident with the flow cytometric results indicating that the cell cycle was arrested at the G1 phase. An elevated phosphor‐eNOSS1177 increased the production of nitric oxide and led to reactive oxygen species‐mediated oxidative stress. Shear flow also regulated epithelial–mesenchymal transition (EMT) by increasing E‐cadherin and ZO‐1 while decreasing Snail and Twist1. The migration and invasion of sheared SW620 were also substantially decreased. Further investigations showed that mitochondrial membrane potential was significantly decreased, whereas mitochondrial mass and ATP production were not changed. In addition to the shear flow of 12.5 dynes/cm2, the expressions of EMT were compared at lower (6.25 dynes/cm2) and at higher (25 dynes/cm2) shear flow. The results showed that lower shear flow increased mesenchymal characteristics and higher shear flow increased epithelial characteristics. Shear flow reduces the malignancy of CRC in their metastatic dispersal that opens up new ways to improve cancer therapies by applying a mechanical shear flow device.
Blockchain is the key technology of Bitcoin and other cryptocurrencies, and it is one of the most exciting technologies changing the world as of late. Targeting at big industrial energy users, this ...paper first presents a new market structure (i.e., transaction rules) under existing blockchain-based electricity transaction platforms to cover popular types of markets such as contract, day-ahead, adjustment and balancing markets; and then focuses on the optimal load management problem for a particular industrial user. The proof-of-work cost from blockchain is also modeled. A key feature of this load management problem is that the user has direct control on its own load. The obtained load control model is much more accurate than existing approaches in which system operators or demand aggregators cannot control load directly and have to rely on inaccurate estimations. As a case study, the pumping load of a water supply plant is investigated to illustrate how the demand load is managed under this blockchain-based market. From the case study, it is found that 18.9% of total cost can be saved under this new market structure.
Quercetin and rutin are popular flavonoids in plant foods, herbs, and dietary supplements. Cyclosporine (CSP), an immunosuppressant with a narrow therapeutic window, is a substrate of P-glycoprotein ...(P-gp) and cytochrome P-450 3A4 (CYP3A4). This study investigated the effects of quercetin and rutin on CSP pharmacokinetics from Neoral and relevant mechanisms. Rats were orally administered Neoral with and without quercetin or rutin. The blood CSP concentration was assayed by a specific monoclonal fluorescence polarization immunoassay. The results showed that quercetin and rutin significantly decreased the C max of CSP by 67.8 and 63.2% and reduced the AUC0−540 by 43.3 and 57.2%, respectively. The in vitro studies indicated that the quercetin and rutin induced the functions of P-gp and CYP3A4. In conclusion, quercetin and rutin decreased the bioavailability of CSP through activating P-gp and CYP3A. Transplant patients treated with Neoral should avoid concurrent consumption of quercetin or rutin to minimize the risk of allograft rejection.
•Improved HS-GC–MS method is simpler to operate and had better applicability.•Coffee beans and coffee power were the products with the highest contents of furan and its derivatives.•Furan and ...2-methylfuran were the residues with the highest detection rates and contents in coffee products.•Research on the control of furan and its derivatives in the production process of coffee products should be strengthen.
The current study analysed concentrations of furan and its derivatives in coffee products commercially available in China based on an improved headspace gas chromatography-mass spectrometry (HS-GC–MS) method and estimated health risks. A total of 101 samples of coffee products on the Chinese market was analysed. Furan (98%, ND-6569 μg/kg) and 2-methylfuran (100%, 2–29639 μg/kg) were the compounds with the highest concentrations and detection rates in coffee products. The mean dietary exposure of Chinese consumers to furan and the sum of furan, 2-methylfuran and 3-methylfuran in coffee products was 0.09 and 0.46 μg/kg bw/day, respectively. For the neoplastic effects of furan, the margin of exposure (MOE) was 14,556 for the mean dietary exposure of consumers. For the non-neoplastic effects of furan, MOEs were 711 and 139 for furan and the sum of furan, 2-methylfuran and 3-methylfuran, respectively. Overall, a health concern is indicated for coffee consumers with MOEs below 10000.
The backbone of Dendrobium officinale polysaccharide (DOP) was reported to be glucomannan. But the dispute continues due to the limitation of conventional analysis methods (e.g., the overlapped NMR ...signals). Herein, we describe an oligosaccharide sequencing analysis that successfully corrects the backbone to mannan. This analysis involves producing oligosaccharide fragments from mild acid hydrolysis of DOP followed by p-aminobenzoic ethyl ester (ABEE) derivatization. Then, a series of oligosaccharides with varied polymerization degrees (DP = 2–10) were isolated and identified by LC-MS profiling, monosaccharide composition analysis, linkage analysis, and 1D-/2D-NMR elucidation. Finally, we conclude that the backbone of DOP is a β-D-1,4-mannan which is confirmed by other analysis such as comparison with reference mannan. This oligosaccharide analysis is more straightforward and reliable by transforming the complicated polymers into oligomers which have more accurate and convincing MS and NMR data.
Display omitted
•An oligosaccharide analysis method was proposed to characterize the DOP.•A series of oligomers and isomers from hydrolyzed DOP were isolated and identified.•An LC-MS method was established to test the oligomers' sugar sequence.•The backbone structure of DOP was corrected to be a β-D-1,4-Mannan.
This study introduces a recent field experiment investigating multiscale terrain–circulation–precipitation interactions. When a synoptic‐scale northeasterly wind prevails under the active East Asian ...winter monsoon, stratocumulus cloud decks with severe rainfall exceeding 100 mm·day−1 frequently occur in the northeastern plain area and adjacent mountains in Yilan, Taiwan. The Yilan Experiment of Severe Rainfall (YESR2020) is a field campaign from November 20, 2020, to November 24, 2020, to survey the physical processes leading to severe wintertime rainfall. The three‐dimensional structure of the wind field and the atmospheric environment can be identified through high temporal and spatial resolution sounding observations, which is empowered by the novel Storm Tracker mini‐radiosonde. During YESR2020, the continuously collected meteorological data of two northeasterly episodes captured the variability of local‐scale wind patterns and the features of the severe rainfall induced by stratocumulus. A preliminary analysis indicated that a local‐scale convergence line could appear over the plain area of Yilan under the northeasterly environmental condition. The precipitation hotspot was located in the mountain region of southern Yilan, where the local winds signified turbulence features. Moreover, the severe rainfall of the two northeasterly episodes spotlighted shallow cumulus under stratus with pure warm rain processes. The results of YESR2020 inspire the arrangement of future field observations to explore detailed mechanisms of heavily precipitating stratocumulus over complex topography.
We conducted the Yilan Experiment of Severe Rainfall (YESR2020) to survey physical processes leading to severe rainfall in the northeastern plain area and adjacent mountains in Yilan, Taiwan, when a synoptic‐scale northeasterly wind prevails under the active East Asian winter monsoon with stratocumulus cloud decks. A preliminary analysis indicated that a local‐scale convergence line appeared over the plain area, and the precipitation hotspot was located in the mountain region of southern Yilan, where turbulence features were apparent. The results inspire the arrangement of future field observations to explore mechanisms of heavily precipitating stratocumulus over complex topography.
To constrain the Mg isotopic composition of the oceanic mantle, investigate Mg isotope fractionation of abyssal peridotites during seafloor alteration, and assess Mg budget in the oceans, a suite of ...32 abyssal peridotite samples from the Gakkel Ridge and Southwest Indian Ridge (SWIR) was, for the first time, selected for high-precision Mg isotope analyses. Although most of these samples are extensively altered, largely by serpentinization and weathering, primary olivine, diopside and enstatite grains are preserved in some samples. Olivine grains from the least altered samples have δ26Mg varying from −0.30 to −0.12‰ (n=7), whereas enstatite and diopside have δ26Mg varying from −0.27 to −0.16‰ (n=7), and from −0.23 to −0.09‰ (n=6), respectively. Whole-rock δ26Mg values range from −0.24 to 0.03‰ with an average of −0.12±0.13‰ (2SD, n=32). Strongly serpentinized peridotites have lower average δ26Mg values (δ26Mg=−0.19±0.07‰, 2SD, n=7) than weathering-dominated ones (δ26Mg=−0.10±0.12‰, 2SD, n=25). Calculated Mg isotopic compositions of fresh mantle peridotites vary from −0.29 to −0.13‰, beyond the previously reported range of the subcontinental lithospheric mantle (−0.25±0.04‰) and the analytical uncertainty (±0.07‰, 2SD). Our study therefore indicates that the oceanic mantle may have similar but slightly heterogeneous Mg isotopic compositions to that of subcontinental lithospheric mantle. Secondary serpentinization does not fractionate Mg isotopes of abyssal peridotites, whereas low-T weathering and formation of clay can result in the enrichment of heavy Mg isotopes in abyssal peridotites. This study also demonstrates that fluid-rock interaction does not necessarily produce rocks with intermediate Mg isotopic compositions. Magnesium isotopes of the rocks thereafter are dependent on the secondary minerals formed. We also conclude that the release of light Mg isotopes into the ocean during alteration of abyssal peridotites can be an important influx of Mg for the seawater Mg budget. Abyssal peridotites with a heavy Mg isotopic signature can be recycled into the mantle in subduction zones and may thus result in heterogeneous Mg isotopic compositions of the oceanic mantle and heavy Mg isotopic compositions of arc magmas.
Indoor photovoltaics are promising to enable self‐powered electronic devices for the Internet of Things. Here, reported is a triple‐anion CH3NH3PbI2−xBrClx perovskite film, of which the bandgap is ...specially designed for indoor light harvesting to achieve a record high efficiency of 36.2% with distinctive high open circuit voltage (Voc) of 1.028 V under standard 1000 lux fluorescent light. The involvement of both bromide and chloride suppresses the trap‐states and nonradiative recombination loss, exhibiting a remarkable ideality factor of 1.097. The introduction of chloride successfully restrains the halide segregation of iodide and bromide, stabilizing the triple‐anion perovskite film. The devices show an excellent long‐term performance, sustaining over 95% of original efficiency under continuous light soaking over 2000 h. These findings show the importance and potential of I/Br/Cl triple‐anion perovskite with tailored bandgap and suppressed trap‐states in stable and efficient indoor light recycling.
I/Br/Cl triple‐anion perovskite material with bandgap of 1.8 eV is tailored for indoor light harvesting, which realizes a record high indoor efficiency of 36.2% with increased open circuit voltage (Voc) and minimal short‐circuit current ( Jsc) loss. The I/Br halide segregation is restrained by Cl‐involvement, realizing a long‐term stability of over 95% after 2000 h.
This paper surveys the extant research in the field of ocean container transport. A wide range of issues is discussed including strategic planning, tactical planning and operations management issues, ...which are categorized into six research areas. The relationships between these research areas are discussed and the relevant literature is reviewed. Representative models are selected or modified to provide a flavour of their functions and application context, and used to explain current shipping practices. Future research opportunities bearing in mind the emerging phenomena in the field are discussed. The main purpose is to raise awareness and encourage more research into and application of operations management techniques and tools in container transport chains.
PDF
